New to tubes, old to hi-fi

[Blair]

I see almost exclusively 7 and 8 pin regulators, but are there any 9 pin regulators? 200V?

I'd like to use a gas regulator for the screens on amp.

Thanks!

[coolhandjjl]

My dream hi-fi has been 40 years in concept. I began assembling components about three years ago and I'm about there. It's a tri-amp all-horn system, Most of the components are vintage, with the oldest being a recently re-capped Marantz 3800 pre-amp. I have one contemporary component, an Ashly Parametric EQ. The speakers use modern drivers and modern plans, custom/hand made by be. All three amps are ss, and I have been enjoying it whole wholeheartedly. But being an obsessive, and one never to be satisfied, I have been reading about the beauty of the horn+tube amp combination.

I'm looking for a tube amp for my mid horns. My mid driver is a 2" Radian 950PB, has a whopping 111 efficiency. The mid horn is a custom designed tractrix horn, the Eliptrac 400, designed by Dave Harris from the Klipsch Forums. I'm running my mids from 400Hz ~ 6500Hz.

The Dynaco ST35 from DynaParts seems like a good candidate, even though I won't need all that power. Price-wise, it's in my budget, can't really spend more, so I don't know if there are any other kits to look at. From what I have researched, most kits are more expensive unfortunately.

Am I on the right track looking at the ST35 kit from DynaParts? Do I need the bias board option?

Thanks in advance, any help would be most appreciated.

[rmyauck]

Also look at Triode Electronics ST-35 kit supported by this form with it's PCB board done by Shannon Parks of this form. It has the advantage of more in production driver tube selection (12BH7A recommended by many to replace the 12AU7) & (so has the potential to be sonically better) , easier to wire, on a bigger easier to work on ST-70 sized chassis. This gives less heat build up from the tubes also.

The PS on PCB gets rid of the can cap (giving you more capacitance for better bass etc. and the use of lower cost caps) and you have room to add a volume control. If you want a cage the Dynaco ST-70 cage will fit that chassis as it's the same size & dynakitparts sells new reproduction if you need one.

Finally Triode's (Output Transformers) are well regarded .

Shannon also sells the PCB board alone for less $ on this form if that's all one wants as some make their own chassis and select their own parts to populate even the board. (there are certain preferences for coupling caps and resistors by some, but they can be changed later if desired) You could also bring your amp cost down if desired by diy your chassis if you found some low cost scrap aluminum & wood for the base etc.

Instead of the adjustable bias kit on the dynakitparts version or the built in adjustable version on Shannon's version a nice upgrade is Dave Gillespie's EFB mod mentioned on this form. It gives longer output tube life, better sonics, and 2-3 W/CH more power. It can actually be added to any easy to drive output tube amp like the EL84 to 7591 tube. It's documented here under enhanced ST-35 performance (in ST-35 Form) and other sites like AK (audiokarma)

Hope that helps!

Randy

[msmpe]

Something else to consider is a single ended (SE) amp. For the mid horm, at 111 (!) you won't need many watts before you're reaching for the earplugs. One suggestion is the EL34 either triode strapped or UL. These amps are real easy to build and lots of circuits to work from. If you don't want to go point to point wiring, combine a couple PCBs: John Broskie at Glass Ware has several PSU boards to choose from and I think Shannon's Clemintine can be made to work (correct me if I'm wrong guys, I don't do too many PCBs). You should be able to put one together for a couple hundred using Edcor iron.

Good luck with your project and show us the results...